​In Acts 16 we have Luke’s account of how Paul and Silas evangelized and planted a church in the Roman Colony of Philippi.  What may very well be the most well-known event of their time in Philippi is what happened after they were arrested and thrown in Prison.  They were charged with sedition for teaching things contrary to Roman law.  That was a serious charge which required the Jailer to place them in the high security section of his prison.  According to Luke, they had spent their evening in prayer and singing hymns.  He also says the other prisoners were listening to them.  Luke doesn’t give any other detail, but I don’t think it a stretch to assume Paul made sure the prisoners heard a clear presentation of the Gospel. 
 
Then at midnight there was an earthquake that shook the foundations of that prison.  The doors had been sprung open and the chains that restrained the prisoners had been loosened.  Assuming the worse, the Jailer prepared to kill himself only to be stopped by Paul who shouted out that no one had escaped.  And then Luke wrote the following: 
 
And he brought them out and said, “Sirs, what must I do to be saved?”  So they said, “Believe on the Lord Jesus Christ, and you will be saved, you and your household.” Then they spoke the word of the Lord to him and to all who were in his house.  Acts 16:30-32
 
While it can be argued that we don’t know what the Jailer meant by saved; we do know Paul’s meaning.  And as Luke points out Paul and Silas went on to explain the Word of the Lord to him and everyone in his household.  As Jesus Christ explained it to Nicodemus in John 3, whoever believes in Jesus Christ for everlasting life will receive everlasting life.  

The main error of those who teach against the secure promise of everlasting life to all who believe in Jesus Christ is that it dishonors God.  I’m reasonably sure that is not their intention.  but they are basically saying Jesus Christ’s death and resurrection fail to satisfy God’s need for justice and his desire to redeem us from our bondage to sin.  They imply something was lacking in God’s redemptive plan or Jesus Christ’s sacrifice that must be made up by us.  However, I’ve never heard anyone explain what that deficit actually was.
 
That leaves their followers with no idea of what they must do to fill in the gap.  Logically, it would seem they either live in fear or surrender to a fatalistic hope for the best approach.  Most people I know that hold the view that salvation can be lost adopt the hope for the best position.  While they can’t say for sure where the line between heaven and hell is; they are pretty sure they’re on the right side of it.  God says there is no reason to live with any uncertainty.  We can have complete assurance by just taking God at His word.  We have been saved by grace through faith without any effort on our part (Ephesians 2:8 & 9).  And God does have a tract record of keeping His word!
 
For when God made a promise to Abraham, because He could swear by no one greater, He swore by Himself, saying, “Surely blessing I will bless you, and multiplying I will multiply you.” And so, after he had patiently endured, he obtained the promise.  For men indeed swear by the greater, and an oath for confirmation is for them an end of all dispute.  Thus God, determining to show more abundantly to the heirs of promise the immutability of His counsel, confirmed it by an oath, that by two immutable things, in which it is impossible for God to lie, we might have strong consolation, who have fled for refuge to lay hold of the hope set before us.  Hebrews 6:13-18